Assessment of Sessile Benthic Communities in Jeju Island, Republic of Korea, Using Autonomous Reef Monitoring Structures (ARMS)

Assessing the effectiveness of artificial structures as a monitoring tool for benthic diversity in temperate reefs is crucial to determining their relevance in reef conservation and management. In this study, we utilized Autonomous Reef Monitoring Structures (ARMS) to evaluate sessile benthic communities that colonized ARMS units after 12 and 34 months of immersion within distinct habitats (coral-dominated and macroalgae-dominated habitats) in Jeju Island, Korea. We used two methods: image analysis of the ARMS plates and DNA metabarcoding of the ARMS units. We found significant differences in the sessile benthic community between the plate faces, installation periods, and habitats. DNA metabarcoding also revealed differences in sessile benthic diversity among habitats. Additionally, we identified the Lithophyllum genus within the crustose coralline algae community, whose dominance might trigger a transition to coral-dominated habitats in Jeju Island. We recommend integrating ARMS image analysis with DNA metabarcoding to enhance and complement studies focusing on benthic diversity. By utilizing ARMS, this study provides valuable information for understanding sessile benthic communities and biodiversity, contributing to an enhanced understanding of the responses of ecological communities to climate change.